Friday, March 29, 2019

Alternative Joints

corner snap-fit tenon pieces wrap the circumference of this box
These boxes are experiments with alternatives to the ubiquitous laser-cut box joints.

(l-r) corner snap-fit tenons, 2 half-tenon designs
half-tenon design

The box joints have graduated to full-fledged mortise and tenons.

The joints between the bottom and the side faces on all three boxes use a technique of fully capturing the tenon a material thickness into the base rather than placing them box-joint style 3/4ths captured flush at the edge.

The right two boxes look like they are assembled from five pieces using edge-lap joints between the vertical faces. But that's not how they work. The end faces are each made from three pieces. Tenons on the end faces are captured half-way into mortises in the left and right faces. Then pieces are added on the outside which provide tenons into the other half of the mortises and cover the holes. These pieces continue down into small mortises in the base. The two boxes experiment with different shapes for the half-tenons -- in one box they are half the depth of the mortise, in the other they are half the height of the mortise.

The leftmost box uses butt joints between the end and side faces. Then the faces are captured with four corner snap-fit pieces that snap into mortises from the outside. Together the four corner snap-fit pieces create a visually continuous band around the perimeter of the box. There are press-fit pieces on the inside that run the length of each face and press into the mortises from the inside. The inside press-fit pieces are easily assembled into the side faces first.

The joints in the above three boxes, except those between the base and the sides, are all significantly more difficult to design than typical box joints.

press-fit tenons all around
This last box eliminates the complexity of the corner snap-fit wrap-around design and uses press-fit tenons on each face to produce the same effect. It's not quite as pretty as the corner snap-fit design, but it's significantly easier to design.